Doctors: Rethink advice to “drink plenty of fluids” when sick

Anyone coming down with an illness has probably heard the advice from a doctor, parent or well-meaning friend: “Drink plenty of fluids.” But medical researchers say there is actually little evidence behind that well-intentioned recommendation, and no clear definition of how much is enough.

In an article published this week in BMJ Case Reports, doctors describe the case of a 59-year-old woman who developed hyponatraemia — a condition that occurs when the level of sodium in the body is abnormally low — from drinking too much water to help with a recurring urinary tract infection. “The effect of illness on the body as well as people’s natural tendency to stop eating and drinking when unwell combine to make the risk of dehydration during illness a real concern,” Dr. Maryann Noronha, an emergency-medicine physician at the Royal London Hospital in England and the senior author of the report, told CBS News. “To counteract this, medical advice has always been to ensure to stay well hydrated during periods of illness,” she said.